In this work, we analyse the effect of network parameters on the judged usability of a collaborative virtual environment. Participants were trained to find the exit of a virtual maze by a trainer, which guided the exploration of the virtual space. An extensive experimental evaluation was conducted by simulating a series of operational parameters (network bandwidth and latency) to assess the reported effectiveness of the training. An objective similarity metric based on processing time per test was also defined and used, as well as subjective user's evaluations. Further, we have successfully correlated subjective evaluation and objective measure by computing the correlation values and showing how the two values co-vary.
{"title":"Performance and user based analysis of a collaborative virtual environment system","authors":"M. A. Rodrigues, R. R. C. Chaves","doi":"10.1145/1321261.1321296","DOIUrl":"https://doi.org/10.1145/1321261.1321296","url":null,"abstract":"In this work, we analyse the effect of network parameters on the judged usability of a collaborative virtual environment. Participants were trained to find the exit of a virtual maze by a trainer, which guided the exploration of the virtual space. An extensive experimental evaluation was conducted by simulating a series of operational parameters (network bandwidth and latency) to assess the reported effectiveness of the training. An objective similarity metric based on processing time per test was also defined and used, as well as subjective user's evaluations. Further, we have successfully correlated subjective evaluation and objective measure by computing the correlation values and showing how the two values co-vary.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129144899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The increasing complexity and costs of surgical training and the constant development of new surgical procedures has made virtual surgical training an essential tool in medical education. Unfortunately, commercial tools are very expensive and have a small support base. Game engines offer unique advantages for the creation of highly interactive and collaborative environments. This paper examines the suitability of currently available game engines for developing applications for medical education and simulated surgical training. We formally evaluate a list of available game engines for stability, availability, the possibility of custom content creation and the interaction of multiple users via a network. Based on these criteria, three of the highest ranked engines are used for further case studies. We found that in general it is possible to easily create scenarios with custom medical models that can be cooperatively viewed and interacted with. Limitations in physical simulation capabilities make some engines unsuitable for fully interactive applications, but they can be used in combination with predefined animations. We show that overall game engines represent a good foundation for low cost virtual surgery applications and we discuss technologies which can be used to further extend their physical simulation capabilities.
{"title":"Evaluation of game engines for simulated surgical training","authors":"S. Marks, J. Windsor, B. Wünsche","doi":"10.1145/1321261.1321311","DOIUrl":"https://doi.org/10.1145/1321261.1321311","url":null,"abstract":"The increasing complexity and costs of surgical training and the constant development of new surgical procedures has made virtual surgical training an essential tool in medical education. Unfortunately, commercial tools are very expensive and have a small support base. Game engines offer unique advantages for the creation of highly interactive and collaborative environments.\u0000 This paper examines the suitability of currently available game engines for developing applications for medical education and simulated surgical training. We formally evaluate a list of available game engines for stability, availability, the possibility of custom content creation and the interaction of multiple users via a network. Based on these criteria, three of the highest ranked engines are used for further case studies.\u0000 We found that in general it is possible to easily create scenarios with custom medical models that can be cooperatively viewed and interacted with. Limitations in physical simulation capabilities make some engines unsuitable for fully interactive applications, but they can be used in combination with predefined animations. We show that overall game engines represent a good foundation for low cost virtual surgery applications and we discuss technologies which can be used to further extend their physical simulation capabilities.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133609312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Schjøth, J. Frisvad, Kenny Erleben, J. Sporring
A number of popular global illumination algorithms uses density estimation to approximate indirect illumination. The density estimate is performed on finite points -- particles -- generated by a stochastic sampling of the scene. In the course of the sampling, particles, representing light, are stochastically emitted from the light sources and reflected around the scene. The sampling induces noise, which in turn is handled by the density estimate during the illumination reconstruction. Unfortunately, this noise reduction imposes a systematic error (bias), which is seen as a blurring of prominent illumination features. This is often not desirable as these may lose clarity or vanish altogether. We present an accurate method for reconstruction of indirect illumination with photon mapping. Instead of reconstructing illumination using classic density estimation on finite points, we use the correlation of light footprints, created by using Ray Differentials during the light pass. This procedure gives a high illumination accuracy, improving the trade-off between bias and variance considerable as compared to traditional particle tracing algorithms. In this way we preserve structures in indirect illumination.
{"title":"Photon differentials","authors":"L. Schjøth, J. Frisvad, Kenny Erleben, J. Sporring","doi":"10.1145/1321261.1321293","DOIUrl":"https://doi.org/10.1145/1321261.1321293","url":null,"abstract":"A number of popular global illumination algorithms uses density estimation to approximate indirect illumination. The density estimate is performed on finite points -- particles -- generated by a stochastic sampling of the scene. In the course of the sampling, particles, representing light, are stochastically emitted from the light sources and reflected around the scene. The sampling induces noise, which in turn is handled by the density estimate during the illumination reconstruction. Unfortunately, this noise reduction imposes a systematic error (bias), which is seen as a blurring of prominent illumination features. This is often not desirable as these may lose clarity or vanish altogether.\u0000 We present an accurate method for reconstruction of indirect illumination with photon mapping. Instead of reconstructing illumination using classic density estimation on finite points, we use the correlation of light footprints, created by using Ray Differentials during the light pass. This procedure gives a high illumination accuracy, improving the trade-off between bias and variance considerable as compared to traditional particle tracing algorithms. In this way we preserve structures in indirect illumination.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130808250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Przemyslaw Musialski, R. Tobler, S. Maierhofer, C. A. Wüthrich
Subdivision surfaces are methods for creating smooth surfaces out of coarse polyhedral meshes. Due to their recursive nature they are ideally suited for adding geometric detail on different resolutions. When modeling real-world surfaces it is possible to extract the fine surface details from a material and apply these on dense meshes in the form of vertex displacements. Material characteristics are a mixture of features at different scales, which can be recovered by a frequency decomposition of an input height map. Applying these sub-bands as displacement in a recursive multiresolution fashion allows the ability to influence or mix details obtained from one or more sources. This paper presents a method for computing multiresolution displaced subdivision surfaces on the GPU that performs in real-time and provides an interactive control over the obtained results.
{"title":"Multiresolution geometric details on subdivision surfaces","authors":"Przemyslaw Musialski, R. Tobler, S. Maierhofer, C. A. Wüthrich","doi":"10.1145/1321261.1321299","DOIUrl":"https://doi.org/10.1145/1321261.1321299","url":null,"abstract":"Subdivision surfaces are methods for creating smooth surfaces out of coarse polyhedral meshes. Due to their recursive nature they are ideally suited for adding geometric detail on different resolutions. When modeling real-world surfaces it is possible to extract the fine surface details from a material and apply these on dense meshes in the form of vertex displacements. Material characteristics are a mixture of features at different scales, which can be recovered by a frequency decomposition of an input height map. Applying these sub-bands as displacement in a recursive multiresolution fashion allows the ability to influence or mix details obtained from one or more sources.\u0000 This paper presents a method for computing multiresolution displaced subdivision surfaces on the GPU that performs in real-time and provides an interactive control over the obtained results.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128125415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
At the moment the noise functions available in a graphics programmer's toolbox are either slow to compute or they involve grid-line artifacts making them of lower quality. In this paper we present a real-time noise computation with no grid-line artifacts or other regularity problems. In other words, we put a new tool in the box that computes fast high-quality noise. In addition to being free of artifacts, the noise we present does not rely on tabulated data (everything is computed on the fly) and it is easy to adjust quality vs. quantity for the noise. The noise is based on point rendering (like spot noise), but it extends to more than two dimensions. The fact that it is based on point rendering makes art direction of the noise much easier.
{"title":"Fast high-quality noise","authors":"J. Frisvad, G. Wyvill","doi":"10.1145/1321261.1321305","DOIUrl":"https://doi.org/10.1145/1321261.1321305","url":null,"abstract":"At the moment the noise functions available in a graphics programmer's toolbox are either slow to compute or they involve grid-line artifacts making them of lower quality. In this paper we present a real-time noise computation with no grid-line artifacts or other regularity problems. In other words, we put a new tool in the box that computes fast high-quality noise. In addition to being free of artifacts, the noise we present does not rely on tabulated data (everything is computed on the fly) and it is easy to adjust quality vs. quantity for the noise. The noise is based on point rendering (like spot noise), but it extends to more than two dimensions. The fact that it is based on point rendering makes art direction of the noise much easier.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131761966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We revisit the assumptions behind traditional image compositing techniques. By analysing the process we separate the colour operations from those for coverage and show that this usefully leads to a more general compositing equation than previously used. We then examine the colour operations in more detail and show how new operations can easily be incorporated in a standard compositor. Practical examples show the new approach and reveal some beneficial effects, not previously achievable within a compositor.
{"title":"Generalised compositing","authors":"P. Willis","doi":"10.1145/1321261.1321284","DOIUrl":"https://doi.org/10.1145/1321261.1321284","url":null,"abstract":"We revisit the assumptions behind traditional image compositing techniques. By analysing the process we separate the colour operations from those for coverage and show that this usefully leads to a more general compositing equation than previously used. We then examine the colour operations in more detail and show how new operations can easily be incorporated in a standard compositor. Practical examples show the new approach and reveal some beneficial effects, not previously achievable within a compositor.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121430347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For wireless network based graphics applications, a key challenge is how to efficiently transmit complex 3D models over bandwidth-limited wireless channels. Recently, several view-dependent 3D progressive mesh transmission schemes have been proposed, which save the transmission bandwidth through only delivering the visible portions of a mesh model. In this paper, we propose to incorporate the illumination effects into the existing view-depend progressive mesh transmission system to further improve the performance. In particular, we propose a novel distortion model, which consists of both illumination distortion and geometry distortion. We further simplify the distortion model in order to compute the rate-distortion function for each segment of a mesh model in a fast manner. Based on our proposed simplified distortion model, given the viewing and lighting parameters, we are able to optimally allocate bits among different segments in real time. Experimental results show that significant quality improvement can be achieved by taking into account the illumination effects.
{"title":"Illumination and view dependent progressive transmission of semi-regular meshes with subdivision connectivity","authors":"Wei Guan, Juyong Zhang, Jianfei Cai, Jianmin Zheng","doi":"10.1145/1321261.1321300","DOIUrl":"https://doi.org/10.1145/1321261.1321300","url":null,"abstract":"For wireless network based graphics applications, a key challenge is how to efficiently transmit complex 3D models over bandwidth-limited wireless channels. Recently, several view-dependent 3D progressive mesh transmission schemes have been proposed, which save the transmission bandwidth through only delivering the visible portions of a mesh model. In this paper, we propose to incorporate the illumination effects into the existing view-depend progressive mesh transmission system to further improve the performance. In particular, we propose a novel distortion model, which consists of both illumination distortion and geometry distortion. We further simplify the distortion model in order to compute the rate-distortion function for each segment of a mesh model in a fast manner. Based on our proposed simplified distortion model, given the viewing and lighting parameters, we are able to optimally allocate bits among different segments in real time. Experimental results show that significant quality improvement can be achieved by taking into account the illumination effects.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128693677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we present a novel user interface design for mobile games using its built-in camera. It is motivated by the problem of limited number of keys on the small keypad of mobile devices. We implement two different ways, with and without the use of markers, to study the effectiveness of the design in a 2-dimensional and 3-dimensional game respectively. The algorithms implemented in the design are lightweight enough so that they are executable in real-time and at the same time, able to produce realism for the games.
{"title":"Design and implementation of a built-in camera based user interface for mobile games","authors":"Khoa Nguyen Tran, Zhiyong Huang","doi":"10.1145/1321261.1321266","DOIUrl":"https://doi.org/10.1145/1321261.1321266","url":null,"abstract":"In this paper, we present a novel user interface design for mobile games using its built-in camera. It is motivated by the problem of limited number of keys on the small keypad of mobile devices. We implement two different ways, with and without the use of markers, to study the effectiveness of the design in a 2-dimensional and 3-dimensional game respectively. The algorithms implemented in the design are lightweight enough so that they are executable in real-time and at the same time, able to produce realism for the games.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124341937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Nowrouzezahrai, P. Simari, E. Kalogerakis, E. Fiume
We present a method for creating a geometry-dependent basis for diffuse precomputed radiance transfer. Unlike previous PRT bases, ours is derived from Principal Component Analysis of the sampled transport functions at each vertex, without relying on pre-projections to secondary bases, such as the Spherical Harmonics or Haar wavelets. It allows for efficient evaluation of shading, has low memory requirements and produces accurate results with few coefficients. We are able to capture all-frequency effects from both distant and near-field dynamic lighting in real-time and present a simple and efficient rotation scheme. Reconstruction of the final shading becomes a low-order dot product and is performed on the GPU.
{"title":"Eigentransport for efficient and accurate all-frequency relighting","authors":"D. Nowrouzezahrai, P. Simari, E. Kalogerakis, E. Fiume","doi":"10.1145/1321261.1321290","DOIUrl":"https://doi.org/10.1145/1321261.1321290","url":null,"abstract":"We present a method for creating a geometry-dependent basis for diffuse precomputed radiance transfer. Unlike previous PRT bases, ours is derived from Principal Component Analysis of the sampled transport functions at each vertex, without relying on pre-projections to secondary bases, such as the Spherical Harmonics or Haar wavelets. It allows for efficient evaluation of shading, has low memory requirements and produces accurate results with few coefficients. We are able to capture all-frequency effects from both distant and near-field dynamic lighting in real-time and present a simple and efficient rotation scheme. Reconstruction of the final shading becomes a low-order dot product and is performed on the GPU.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120916698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A motion trend analysis method is proposed to reconstruct human motion from un-calibrated monocular video. In this paper, relocation of human subject is the main concern, which is one of the most difficult parts in motion reconstruction and critically affects the accuracy of human posture generation. Numerical studies are conducted on experiments from synthetic and real video data to demonstrate the correctness of the recovered human translation in the proposed system.
{"title":"Monocular reconstruction of human translation in motion sequence by MTA","authors":"Li Zhang, Ling Li","doi":"10.1145/1321261.1321275","DOIUrl":"https://doi.org/10.1145/1321261.1321275","url":null,"abstract":"A motion trend analysis method is proposed to reconstruct human motion from un-calibrated monocular video. In this paper, relocation of human subject is the main concern, which is one of the most difficult parts in motion reconstruction and critically affects the accuracy of human posture generation. Numerical studies are conducted on experiments from synthetic and real video data to demonstrate the correctness of the recovered human translation in the proposed system.","PeriodicalId":360852,"journal":{"name":"Conference on Computer Graphics and Interactive Techniques in Australasia and Southeast Asia","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128771303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：